Lithium-ion cell modeling from impedance spectroscopy for EV applications

Investigation dealing with lithium batteries modeling has a growing importance in researches on energy storage for hybrid and electric vehicles. This is especially due to the ever-increase of the applications variability of this kind of battery and the high performances required in severe complex applications. In this paper, we present a model for a 100 Ah high-energy-density Lithium-ion Polymer cell, based on impedance spectroscopy measurements. This model, based on an equivalent-circuit approach, is characterized by its simplicity. At the same time it takes into account several important phenomena that occur into the lithium cell, such as the dependence of a part of the internal resistance and the open-circuit voltage on the state of charge.